Migration

East Coast population leaves breeding colonies mid- to late Jul and wanders widely north and south along coast and inland up major waterways; w. Mexican population moves north to Salton Sea, CA; Gulf Coast population wanders along gulf; and Caribbean population moves among islands. During postbreeding period, Laughing Gulls (particularly young) concentrate near garbage dumps and on wet, open fields, including those at airports.

Florida and West Indian birds largely resident; northern birds migratory. In Sep and early Oct, smaller flocks coalesce into larger flocks along coast, often on sandy beaches, and begin directed southward migration.

Majority of band recoveries are from Central America and nw. South America; significant proportion of North American Laughing Gull population winters in that general region (Southern 1980). Next highest percent of band recoveries are, in decreasing order, from Florida, Cuba and vicinity, and Gulf Coast (Southern 1980). Mean distance between banding and recovery sites for Dec–Mar was 2,100–3,000 km (Southern 1980).

Routes

Fall dispersal of hatching-year birds characterized by northward movements before migration (Belant and Dolbeer 1993b). East Coast population migrates along coast in spring and fall, but individuals may scatter inland. Migrates slowly to Florida and Texas, where some birds overwinter; others continue to Mexico. Band recoveries indicate that northeast population migrates greater distances and is recovered farther south during winter than Gulf Coast population (Southern 1980, Belant and Dolbeer 1993b; see Table 1). Leapfrog migrations: significantly more Gulf Coast birds winter along the Gulf Coast than do northeast birds; significantly more northeast birds winter in Central and South America (Belant and Dolbeer 1993b). An immature found at Lihue, Kauai, HI, in Dec 1979 had been banded by JB at Barnegat Light, NJ, that year (Telfer and Shisler 1981). Highest Christmas Bird Count totals for the U.S. come from Florida, with 80,000 at St. Petersburg landfill (1977) and 41,562 at Dade Co. landfill (1981; Stevenson and Anderson 1994).

Timing

See Figure 5 . Northward migration starts in Mar; most adults on breeding colonies by mid-May (Southern 1980). Some southward movement in Aug and Sep, when recoveries are from Massachusetts to N. Carolina; rapid increase in distance between banding site and recovery site from Oct to Dec (Southern 1980). Band recoveries of 3,662 Laughing Gulls banded in North America from 1924 to 1991 indicate fall migration initiated in Oct (Belant and Dolbeer 1993b). Band recoveries indicate adults return to breeding areas between Mar and May (Belant and Dolbeer 1993b).

Before migration in Sep and Oct, may form large flocks and sit on ocean waters or beaches (Stone 1937). Migrates in small to intermediate-sized flocks; never migrates in as large flocks as Franklin’s Gull. In fall along East Coast, flocks mix with other gulls, e.g., Ring-billed (Larus delawarensis) and Herring gulls on landfills, near outfalls, or on fishing piers. Southward migration is leisurely. In spring, large concentrations gather at rich food sources such as on Delaware Bay where horseshoe crab (Limulus polyphemus) eggs are abundant (see Fig. 3). Mixes with Herring Gulls and shorebirds while feeding on crab eggs, but usually prefers conspecific groups on sandbars.

No data.